In a crisis situation, toxic gas can be released into the air, blocking routes for emergency responders. Rescue workers must be able to compute the shortest and safest paths in the presence of toxic gas dispersions that move dynamically with changing wind speed and direction. To model this, the authors developed weather retriever software, which fetches weather details about a particular location from the Internet and acts as the station for atmospheric measurements for the Aloha plume-modeling software. The authors also explored options for displaying this dynamic plume on a geographic map.